Question

what is animal tissue and its type

Answer 1

Animal tissues are grouped into four basic types: connective, muscle, nervous, and epithelial. Collections of tissues joined in structural units to serve a common function compose organs.


There are four types of tissues found in animals: epithelial tissue, connective tissue, muscle tissue, and nervous tissue.

Answer 2

Animal Tissues and their Function:

The structure of the cell varies according to its function. The tissues are different and are classified into four types:  

• Epithelial tissue

• Connective tissue

• Muscular tissue and  

• Neural tissue.

Epithelial Tissue

• Epithelial tissue is commonly referred to as epithelium. The epithelial tissue forms the outer covering or lining for some part of the body. It is composed of closely packed cells, arranged in flat sheets. Epithelial tissues forms the surface of the skin, lines many cavities of the body and covers the internal organs.  

• There are two types of epithelial tissues - Simple Epithelium and Compound Epithelium.

• Simple epithelium is composed of single layer of cells. It functions as a lining of cavities of body, ducts and tubes.  

• Compound epithelium or stratified epithelium is made of two or more cell layers.It functions as a protective covering, like it does in our skin.

Modifications of Simple Epithelium

• On the basis of structural modification the simple epithelium is divided into three types: Squamous, Cuboidal, Columnar cells.

• The squamous epithelium is made of a single layer of irregular, thin, flattened cells with irregular boundaries. They are found in the walls of blood vessels and in air sacs of lungs. They are involved in functions like forming a diffusion boundary.  

• The cuboidal epithelium is made of a single layer of cube-like cells. They are commonly found in ducts of glands and tubules of nephrons. Its main functions are secretion and absorption.  

• Columnar epithelium is composed of single layer of tall and slender cells. The free surface of these cells may have microvilli. They are found in lining of stomach and intestine. It helps in secretion and absorption.  

• If the columnar epithelium bears cilia on their free surface they are called ciliated epithelium. They help to move particles or mucus in a specific direction. They are present in the inner surface of branchioles and fallopian tubes.  

• Compound Epithelium

It is made up of more than one layer of cells and has a limited role in secretion and absorption. They main function is to provide protection against stress. They cover dry surface of skin, moist surface of buccal cavity, pharynx and inner lining of salivary glands.

Connective Tissue

• Connective tissues are the most abundant tissues of complex animals. They link and support other tissues/organs of the body. The connective tissues include cartilage, bone, adipose, and blood. All connective tissues except blood, secrete structural proteins called colagen or elastin.  

• Connective tissues are classified into three types - Loose Connective tissue, Dense Connective tissue, and Specialized Connective tissue.  

• Loose Connective tissue - These tissues have cells and fibres that are loosely arranged in a semi-fluid ground substance.  

• Areolar tissue - It is present beneath the skin, it serves as a framework support for epithelium.

• Adipose tissue - This type of tissues is specialized to store fats.

• Dense Connective tissue - Fibres and fibroblasts are packed compactly in dense connective tissue. Tendons are dense regular tissue that attach skeletal muscle to bones and ligaments attach bone to another bones. Collagen is the dense irregular tissue present in the skin.

• Specialized Connective tissue - Cartilage, bones and blood are types of specialized connective tissue.  

• Cartilage - Cartilage is solid, pliable tissue. The cells of this tissue is chondrocytes. Cartilage is present in the tip of the nose, outer ear joints, between bones of vertebral column.  

• Bones - They are hard and non-pliable, rich in calcium salts and collagen fibres. It provides structural frame to the bosy. The bone cells are osteocytes. The bone marrow in some bones is the site of production of blood cells.  

• Blood - It is a fluid connective tissue. It contains plasma, RBCs, WBCs and platelets.  

Muscle Tissue

Muscle tissues are made of long cylindrical fibres, arranged in parallel arrays. These fibres are composed of fine fibrils known as myofibrils. The contraction and relaxation of moves the body to adjust to the changes in the environment. Muscles are of three types skeletal, smooth, and cardiac.  

• Skeletal Muscle - Skeletal muscle is also known as striated muscle. It is closely attached to the bones, example biceps.  

• Smooth Muscle - Smooth muscle fibres do not have striated. The wall of internal organs contain smooth muscles.  

• Cardiac Muscle - Cardiac muscle tissue is a tissue present only in the heart. Cell junctions fuse the plasma membranes of cardiac cells. Communication junctions allow the cells to contract as a unit.  

Neural Tissue

Neural tissues controls the body's responses to the changing conditions. Neurons are the units of neural system, they are excitable cells. The glial cells forms the rest of the neural system, they protect and support neurons. Its functions in receipt, processing and transferring information.